Method for transmitting PPDU in wireless local area network and apparatus for the same

• US 8,873,582 B2
• Filed: 04/07/2011
• Issued: 10/28/2014
• Est. Priority Date: 04/08/2010
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Noh, Yu Jin, Lee, Dae Won, Seok, Yong Ho
• Primary Examiner(s): Gillis, Brian J
• Assistant Examiner(s): Keller, Michael A
• Application Number:
  US13/082,025
• Publication Number:
  US 20110249660A1
• Time in Patent Office: 1,300 Days
• Field of Search: 370/468, 370/470, 370/476, 370/505, 370/506
• US Class Current: 370/468
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2603 Signal structure ensuring backward compatibility with legacy system
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0085 when channel conditions change
• CPC Class Codes: H04W 28/065 using assembly or disassembly of packets
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A method of transmitting a data block in a wireless communication system is provided. The method includes generating a data block used for multi-user transmission, the data block comprising a first control field and a data field for a plurality of users, the first control field indicating multi-user transmission of the data block, the data field comprising a plurality of data units, each data unit comprising a PSDU(PLCP(Physical Layer Convergence Procedure) Service Data Unit) for each user and padding bits which are appended to the PSDU for each user; and transmitting the data block to the plurality of users; wherein the number of the padding bits in each data unit is determined so that lengths of the plurality of data units are same and the number of the padding bits in each data unit is determined by N_sym, N_DBPS,k, N_PSDU,k, where N_sym denotes the number of OFDM symbols of the data field, N_DBPS,k denotes the number of data bits per OFDM symbol for k-th user, and the N_PSDU,k denotes the length of the PSDU for k-th user.

Claims

1. A method of transmitting data blocks in a wireless communication system, the method performed by a transmitter and comprising:

generating a data block in a Medium Access Control (MAC) layer;

generating a first padded data block by appending at least one padding octet to the data block when a length of the data block is smaller than a target length in the MAC layer;

delivering the first padded data block from the MAC layer to a physical (PHY) layer;

determining a number of bits for a padding bit sequence of the first padded data block in the PHY layer, the number of bits for the padding bit sequence being smaller than one octet;

generating a second padded data block by appending the padding bit sequence to the first padded data block in the PHY layer; and

transmitting, over an operating channel, a physical layer convergence procedure (PLCP) protocol data unit (PPDU) to a receiver, the PPDU including a signal field, a Very High Throughput-Signal-A (VHT-SIG-A) field, a Very High Throughput-Signal-B (VHT-SIG-B) field, and the second padded data block;

wherein the signal field includes information used for calculating the target length,

wherein the VHT-SIG-A field includes group information indicating the receiver to receive the PPDU,

wherein the VHT-SIG-B field includes information indicating the length of the data block before padding, and

wherein the number of bits for the VHT-SIG-B field is determined based on a bandwidth of the operating channel.

2. The method of claim 1, wherein the number of bits for the padding bit sequence of the first padded data block is determined by:

N_PAD={Nsym N_DBPS−

8 PSDU_length−

(16+6 N_ES)} mod 8

wherein;

N_PAD indicates the number of bits for the padding bit sequence and ranges from 0 to 7;

Nsym indicates a number of orthogonal frequency division multiplex (OFDM) symbols corresponding to the target length;

N_DBPS indicates a number of data bits per symbol;

PSDU_length indicates the target length

N_ES indicates a number of binary convolution coding (BCC) encoders; and

‘

mod’

denotes a modulo operation.

3. A wireless apparatus comprising:

a processor; and

a transceiver operatively coupled to the processor and configured to transmit and receive a data block,

wherein the processor having a Medium Access Control (MAC) layer and a physical (PHY) layer is configured to;

generate a data block in the MAC layer;

generate a first padded data block by appending at least one padding octet to the data block when a length of the data block is smaller than a target length in the MAC layer;

deliver the first padded data block from the MAC layer to the PHY layer;

determine a number of bits for a padding bit sequence of the first padded data block in the PHY layer, the number of bits for the padding bit sequence being smaller than one octet;

generate a second padded data block by appending the padding bit sequence to the first padded data block in the PHY layer; and

instruct the transceiver to transmit, over an operating channel, a physical layer convergence procedure (PLCP) protocol data unit (PPDU) to a receiver, the PPDU including a signal field, a Very High Throughput-Signal-A (VHT-SIG-A) field, a Very High Throughput-Signal-B (VHT-SIG-B) field, and the second padded data block,

wherein the signal field includes information used for calculating the target length,

wherein the VHT-SIG-A field includes group information indicating the receiver to receive the PPDU

wherein the VHT-SIG-B field includes information indicating the length of the data block before padding, and

wherein the number of bits for the VHT-SIG-B field is determined based on a bandwidth of the operating channel.

4. The wireless apparatus of claim 3, wherein the number of bits for the padding bit sequence of the first padded data block is determined by:

N_PAD={Nsym N_DBPS−

8 PSDU_length−

(16+6 N_ES)} mod 8

wherein;

N_PAD indicates the number of bits for the padding bit sequence and ranges from 0 to 7;

Nsym indicates a number of orthogonal frequency division multiplex (OFDM) symbols corresponding to the target length;

N_DBPS indicates a number of data bits per symbol;

PSDU_length indicates the target length

N_ES indicates a number of binary convolution coding (BCC) encoders; and

‘

mod’

denotes a modulo operation.